Cassidy was born in
Sudbury, Suffolk; his father Francis Arthur Michael Cassidy had played for
Norwich City before
World War II. He returned to Cambridge for the
1975–76 season after finishing his spell in America and finished his Cambridge career with 54 league appearances and 13 goals. as well as running the Black Bull pub in
Launton and the Shakespeare pub in
Bicester, before moving to
Wadebridge in
Cornwall where he ran the Molesworth Arms for almost 20 years. He died on 19 May 2008 after suffering from a short illness.{{cite news ==Notes==